For instance, mutant mice with either forebrain-specific deletion of BDNF or TrkB deletion in striatal progenitors, display hindlimb and forelimb clasping phenotype, which has also been observed in transgenic lines with motor dysfunction or degeneration, including HD mouse models (Baquet et al., 2004; Baydyuk et al., 2011). This evidence concerns the gene NTRK2 and Huntington disease.